Question

I am reading some VB6 to convert to C#. What does this line mean? Is 0& equivalent to IntPtr.Zero?

//'Get a Device context
hdc = GetDC(0&)

This value is used to pinvoke, so I’m not sure IntPtr.Zero makes sense since we need to be selecting some object.

OldFont = SelectObject(hdc, ObjFont)

Note, ObjFont is populated via

//'Get the Window's font
ObjFont = SendMessage(hwnd, WM_GETFONT, 0, 0&)//there's that mysterious 0& agaain.

Answer 1

It is a (VB6) type declaration character. Have a look at this question for more details on these.

In your example VB6 code it is forcing 0 to be a Long (4 bytes) as it would otherwise be an Integer (2 bytes)

It is the same as doing this long hand approach again VB6 code:

Dim lParam as Long
lParam = 0
ObjFont = SendMessage(hwnd, WM_GETFONT, 0, lParam)